Children and Early Weight Bearing

Recently questions about the potential dangers of weight bearing “too early” have been raised. I hope to answer some of these common misconceptions with this post!

One question was posed to me by a good friend and Pediatric OT:

“I have a PT clinical question for you. My sister in law has the cutest 4 month old. He is hitting all his milestones, and is such a great kid. Very active, but super mellow. Since he was 2 months, she would play with him by having him stand and then squat down and up. He think it’s great fun. She continues to do this with him, which I think is great because he is building up those muscles. However, her grandmother told her she shouldn’t do that because it will cause him to be bow-legged. Now my sister in law is freaking out.”

Background

Bowleggedness is clinically referred to as genu vara or tibia vara. It is identified by outward bowing of the lower leg in relation to the thigh, giving the appearance of an archer’s bow. This condition is common in toddlers and young children, and usually not cause for alarm. See this post for red flag gait presentations.

The physiologic form of tibia vara is something that children outgrow, and the standard treatment of choice is in fact weight bearing activities in proper alignment, with a good support surface for bearing weight evenly through.

Most cases are thought to be due in part to the child’s position in utero. The curvature remains noticeable until the child develops the necessary muscle strength in their lower extremity and trunk to weight bear fully and symmetrically.

According to the Children’s Orthopedic Institute,

“Generally, bowed legs is a benign condition that does not require special shoes or braces. The bowing should improve as the child grows, typically from 15 to 18 months until 3 years of age. Bowed legs presenting beyond the age of 3 or bowleggedness that only occurs in one leg, but not the other can be a sign of a more serious condition, such as Rickets or Blount’s disease.”

Differential Diagnosis

Blount’s disease is a condition in which the abnormal growth in the upper part of the tibia causes the legs to bow. Unlike non-pathological etiologies for bowed legs, the bowing with Blount’s disease will be progressive.

Bowed legs in a toddler can also be due to Rickets, which is a deficiency of Vitamin D. This rarely occurs in developed countries like the United States, because many foods are fortified with Vitamin D. More commonly, rickets is secondary to a problem with absorbing or metabolizing Vitamin D.

A blood test may be done to rule out a Vitamin D definiciency and radiographic testing will help to rule out Blount’s disease.

Neither of these conditions are brought on by early weight bearing. Of course we do not want to rush children through developmental milestones, as each stage provides important physical, cognitive and social opportunities and growth. However there is nothing wrong with allowing a child to play in different positions. In fact, by allowing some upright time and early weight bearing (with support of course), we can facilitate bone mineralization and growth.

Weight Bearing Basics

Weight bearing is defined as the ability of the body to hold or bear its own weight in any given position.

Gross motor development of the healthy child progresses from the horizontal position – lying where he or she is placed on the front or on the back – to the upright standing position and to walking. During this sequential development, the child begins to support and to carry his/her own weight from within and the necessity for having a large surface, or several points of contact between his own body and the floor diminishes.

In Supine the child has the most surface contactNext the child begins to play with weight bearing through elbow in sidelyingNow able to sustain prone position, the child begins pushing up through forearms and then handsNext rolling becomes part of the child’s repertoireFollowed by crawling: commando then four point

Some children may experiment with bear crawl stance, weight bearing through hands and feetChild begins to weight bear through feet alone to prepare for independent standing and walking

This is the basic developmental weight bearing sequence. It is important to note, that if the child is unable to maintain a given static position then progressing from one position to the next through a process of dynamic movement cannot be attained. As Pediatric Therapists we can help each child to gain the static strength, stability and balance in each developmental position to encourage transitions between positions and assist with dynamic mobility and control. This occurs by allowing the child to experience each developmental position to promote central nervous system and musculoskeletal system development. Exploration and active play are instrumental in our child’s development!